What role does "obligatory caution" play in Sunni Islam?

Ayatollah Khamenei's FAQ page mentions several times the notion of "obligatory caution". One example is: > Permission of Her Father for Marriage. If the girl is virgin, it is necessary – by obligatory caution – to obtain the permission of her father/paternal grand father for her marriage. M. B. al-Sadr in *Principles of Islamic Jurisprudence [translated]: According to Shi'i Law*, 2003 (Google Books ) describes it as: > The primary principle to be observed in matters of probable prohibition or obligation is therefore caution, avoiding what we suspect to be unlawful and accomplishing what we think obligatory. ... The exercise of caution is rationally obligatory in cases of doubt. And it's mentioned on Ayatollah Lankarani's webpage also. Conspicuously absent from my search results is the notion of "obligatory caution" in Sunni Islam, and I'm wondering if Sunni scholars have a different stance or attitude towards obligatory caution. **Question**: What role does "obligatory caution" play in Sunni Islam?